Charles a



C. A. PRATT.

CUTTER ARM FOR MINING MACHINES.

APPLI nan JAN 1916. 1,322,819. Patented Nov. 25, 1919.

outer flange 4 of each CHARLES A. PRATT, or CHICAGO, IILIQINoIs, AssIeNon rro GOODMAN MANIIIAcTUnING COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

CUTTER-ARM FOR MINING-MACHINES.

Specification of Letters Patent.

Patented Nov. 25, 191e.

Application tiled January 22, 1916. Serial No. 73,567.

Figure 1 is a plan view of a cutter arm embodying the invention, with parts omitted.;v

' Fig. 2 is a sectional view taken on line 2-2 of Fig. 1.

Fig. 3 is a'plan view showing the entire cutter arm.

Like numerals refer to like parts throughout the several figures.

The cutter arm is made up of a suitable frame-work about which the cutter chain passes, the cutter chain sliding in a guiding groove on the cutter arm; The frame of the cutter arm is made up of two side members 1, each having an enlargement or a thickened portion 4 at one side, and a thinner portion 8 connected therewith. In the construction shown, the side members are I-shaped in cross section, and I preferl to use as these side members rolled beams, such for example, as ordinary railway rails. When this construction is used, the enlargement 4 forms one flange of the rail, preferably the head thereof, while the thinner portion 8 forms the web, the base forming the flange 2. The bases or flanges 2 of these side members are opposed to each other and are separated by a space 3. Connected with the side member are the two guiding members 5. These members are preferably rolled members andare provided at their outer edges with the Hat projecting ,faces 6 engaged by the chain and the `depressed face 6l which engages the flange of the side member, there being a space between said flange and the faces 6 which form grooves for guiding parts on the cutter chain. The guiding members 5 are fastened to the flange 4 in any desired manner, as by the fastening devices 5. These guiding members have projecting parts 7, which enside members 1 between the two fianges. I prefer to make the projecting parts 7 curved. The web 8 of each side member is preferably providedV with grooves 9 on the opposite sides thereof, into which the projecting parts 7 fit.

In the operation of the device, the chain exerts a pressure on the faces 6-6, tending gage the to separate said faces, and in many instances this pressure at times becomes so great as to make 1t difficult to hold the guiding members in place and in proper relation to each y other. By means of the present construction this difficulty is obviatedas the fulcrum of each guiding member is located at the point where the projection 7 engages the web 8 and hence the lever arms are thus so arranged as to permit the construction to resist the pressures without the guiding members being spread apart. It is very essention, for the proper operation of the chain, that the distance between the faces 6 be maintained at all times, and I have found that by means of the present construction this result is attained.

In making up the device, where the side members are railway rails, in ordery to secure theproper accuracy as tothe distance between the faces 6 and 6, I prefer to plane off the faces 10 of the ball of the rail, the face 10 on one side and the groove 9 on that side being planed simultaneously so as to insure accuracy.

I have described in detail a particular construction embodying the invention, but it is of course evident that the parts may be varied in certain particulars without departing from the spirit of my invention, and I therefore do not limit myself to the particular construction shown.

I claim:

1. A cutter arm for mining machines, comprising two side members, said side members having an I-shaped cross section, consisting of two separated flanges and a web connecting said flanges, two side chainguiding members associated with each side member, said guiding members fastened to one of the flanges of the side member and havin@ pro-y jecting portions which project outwarzdly to form a guiding groove for the chain, said guiding members also having rearwardly projecting portions which project beyond said flange and taking the strain when the chain is cutting, and a connection between Vsaid rearwardly projecting port-ions and the web of the side member with which they are connected so that said web resists thev in ovement of saidprojections due to pressure from the chain.

2. A cutter arm for mining machines, con'i'- prising two side members, each of said side members lprovided with flanges connected A"toI gether by a web, two side guiding members connected to the outer vflange of each side member on opposite sides thereof and prov jecting outwardly' so ask to form a guiding grooif'e'- for the cutter chain',` said guiding members having rearwardly projecting portions .which project :beyond the lflange and engage the web of said side member.

3. Acutter arm for mining machines, coirprisingtwo side members, each oit said side members provided with flanges connected together by a web, two side guiding members connected to the outer fiange of each side Y member on opposite sides thereof and proenga-ge the web of saidside member, the saidv web :provided with 4grooves on opposite sides thereof into fwhich saidrearwardly vprojecting portions are received;

t.. A cutter' armfor mining machines, comn prising two side members, each of said side members comprising a thin web :portion and a thick outer portion connected together. two guiding members connected tothe .thick outervportion of each side member on opposite sides 'thereofand projecting outwardly so as to form a 'guiding groove forthe cutter chain, said guiding members having rrearwardly' rojecting portions whichjprojcct iiiwardly leyond Ithe thickportion `and pai-t way along the vwebportion, and a connectiiin. between the said rearwardly .projecting portions of the guiding` members and said web portion so-that the web portion resists the movement `of said rearwardly projecting portionsof the guiding members dueto pressure from the chain.

site sides thereof and projecting outwardly Y so fas to form a guiding groove for the cutter chain, said guiding members having rearwardly Vrojecting portions which project inwardly ieyond the thick portion and part way along the web portion, the said web por- -tion provided with grooves, and the 'projectiig portions of the guiding members engaging said web so that the web re.

the chain. y

8....A chain guiding memberl for cutter` arms for mining machines .compri-sing two V thc pressure from the chain.

6. A cutter arinfor mining machines, com

risin .two side lmembers each of said Side g Y n members provided with flanges connected together by a web, two guiding members connected to the outer flange of each Vof said members on opposite sides thereof and projecting outwardly so as to forni a guidinggroove "for the cutter chain, said 'guiding members having rearwardly projecting portion-s which project beyond the flange andV Part way along the web, said projecting portions bent inwardly toward each other and the movement Aof the Vrearwardlyprojecting portions of said guiding members due to pressure of the chain tending toseparatefsaid guiding members. v

7. A cutterarm for mining machines comprising twochain lguides ongopposite sides thereof, each guide comprisinga thick lportion, one side of which provides a backing' for .the chain, a thiiif portion connected with the other .side ofsaid thick portiointwolguiding members' secured to each` lhickfportion on opposite sidesethereof-andprojecting outwardly so. as to form a guiding groove foithe` cutter chain, said .guiding members havking rearwardly projecting portii'inswhich project inwardly beyondsaid thick portion and part way along the thin portion, and a connection between the saidrearwardly projecting portions and thethin portion so that the thin portion resiststhe movement of the saidfrearwardly projecting portions of the guiding Ymembers "due to the pressure from side meinberaeach of said side members provided with vseparated flanges connected together by 1an intervening web, two guiding members connected to the outer flange of each side member on opposite sides thereof and projecting outwardly so as tolform a guiding :groove for the cutter chain, said guiding members vhaving rearwardly projecting portions which project beyond the flanges, the endsof said rearwardly .project-V ing por-tions engaging said web', a portion of said rearwardly projecting portions between said ends and 'said angebei'ng free from said web. Y

In testimony whereof, I aiiix -signature in the presence of two witnesses vthis Zthday of January; 1916. n i CHARLES A. PRATT. Witnesses: MINNIEM-LINDENAU, .CHRISTINA DEANS. 

